1. Field of the Invention
The present invention relates to the technical field of display device, and in particular to a thin-film transistor (TFT) liquid crystal display (LCD) device, a substrate, and a manufacturing method thereof.
2. The Related Arts
TFT LCD device is a member of the liquid crystal displays family and using TFT techniques helps improve image quality. The core components of a TFT LCD comprise a liquid crystal panel and the liquid crystal panel is composed of a TFT substrate, a color filter substrate, and a liquid crystal layer interposed between the two. An alignment layer is present between the liquid crystal layer and the TFT substrate or the color filter substrate and the alignment layer makes the liquid crystal contained in the liquid crystal layer showing a predetermined pre-tilt angle.
As shown in FIG. 1, FIG. 1 is a schematic view showing a planar structure of a pixel of conventional multi-domain vertical alignment (PSVA) TFT substrate. The TFT substrate comprises a glass substrate 10 and signal lines 11, scan lines 12, a pixel electrode 13, a common electrode 14, and a TFT that are formed on the substrate 10. The signal lines 11 and the scan lines 12 both are a plurality of conductive lines arranged in an equally-spaced manner and intersect each other as being horizontally and vertically laid, respectively. Two adjacent ones of both the signal lines 11 and the scan lines 12 collectively enclose and delimit one pixel. The pixel electrode 13 is set within a display region of the pixel and is generally divided into four zones. The pixel electrode 13 has a central portion that is of a cruciform shape and a plurality of fingers 16 extends from the cruciform central portion in directions toward a circumference of the pixel display region. Slits 17 are defined between adjacent fingers of the pixel electrode 13. The common electrode 14 extends in the direction of the scan lines 12 from one side of the pixel to the opposite side. When a potential difference exists between the pixel electrode 13 and the common electrode 14, the liquid crystal molecules tilt in four directions. Through optic or thermal reactive material contained in the liquid crystal or the alignment layer, the liquid crystal molecules on the surface of the alignment layer can be fixed to form a predetermined pre-tilt angle in the four directions.
When the TFT is in operation, the vertical component of electrical field above the electrode slits 17 is relatively small and the liquid crystal molecules cannot show the most effectively tilting, whereby the brightness of the area of the electrode slits 17 is dimmer than the area of the pixel electrode 13. Further, the brightness and the transmittance of the pixel are closely related to the width of the electrode slits 17. During the process of manufacturing, when abnormality of the width of the electrode slits 17 occur, a defect of local irregularity of the brightness of an image is identified, resulting in quality problems of the image.